help!!!!! brakes gone wrong,again!

hi all, as u probably know i posted on here a few months ago about brake probolems, and yes ino im creating another post,but everyone has probably got bored of that one by now,so here goes again! i have now fitted a new master cyclinder to my series 3 88 inch, and for some reason,cant get a sensible pedal,its ither right at the top, and they lock on after a good 6 miles,or it just hits the floor! they are all adjusted up,and iv bled them around 5 times now, and i cant figure out for love nor money whats wrong, it has new wheel cyclinders all round,and flexi pipes,and now a new master cyclinder,and yes a decent one to, trw one! so i now have no brakes again, has anyone had this probolem? an if i manage to get a pedal,it is unpredictable,dont know wheather its gonna hit the floor or be there? oh and thought id mention its the type with the two pipes, and the fluid resovour is seprate,held by the cluch pedal box screw.and yes i have renewd the feed pipe from the fluid resovour aswell! has anyone else had this probolem?? i dont want to sell her,but shes causeing me alot of grief,more than normal,much more!!

thanks tom

Have a look at the servo mate. The pedal attaches to a rod on the servo, that assists the pedal etc etc. When it's at the top and it takes forever to work it sounds like servo has lost vacuum. Going straight down and not doing anything could also be servo linkage issue.

Vacuum pump, pedal connection to servo and servo effectiveness...

Let us know

Did you get any air out at each wheel each time you bled them. If there was air then look at that corner of the car for air being sucked in.
I know you've replaced the master cylinder but when you say they lock on a few miles down the road and sometimes they're not there it would lead me straight to the master cylinder. When they lock on you can try loosening off the line from the master cylinder and see if the fluid is under pressure.
I have had bad master cylinders straight out the box before. Even good quality ones. If you don't have a servo I would look there first. Maybe even find a known good one or a cheapy one to try.

yea i havent got a servo on mine,unfortunatly,but yea i had a britpart one before and it was ****e,but it seems to be the drivers side front that binds,no matter what you do to adjust it,and no matter how much i bleed it there is always air coming out of the bleed pipe! so it may be that wheel causeing the probolem! when i put the new master cylinder on and bled the brakes,it had a pedal half way,so i went round all of the wheels,one by one,and adjusted them up,put my foot on the pedal,and it went streight to the floor! thanks for you imput tho,i have all day now,so ill just chip away at her!

just tryed driving it again,bled the front brakes about 10 times,and the back,and now the pedal just hits the floor! im loosing my patiance with it,becuase thats the second master cylinder its had,its had 4 new wheel cyclinders,and now it just wont work properly atall,it ither takes two pumps to get them to work,or its just right at the top again! its just ****e,no matter what you do to it!

Is it a spongy drop to the floor or zero resistance?

After all the bleeding I'm guessing there is fluid almost everywhere. Is your fluid level dropping after pumping the breaks lots?

Going straight to floor would point towards something releasing the pressure.

Get someone to pump the break top to bottom while you go round and check every individual union. Listen for hisses, look for any release of fluid. Even the smallest leak will feel like a loose pedal because of the pressures involved.

The T piece that feeds the rear brakes on my 90 had a miniscule leak and showed itself the same way

yea, i had the front drivers side appart,becuase thats the one binding, and the top shoe retern spring had flung off,and wedged imbetween the shoe and back plate,and i peeled the boot back,and the wheel cylinder has a slight weep,witch i would guess is why i cant seem to get rid of the air,when bleeding the system! so hopefully thats the probolem, because it only takes two pumps and its got a decent pedal,so i thought if the spring had come off,then maby the master cyclinder has to come back up and recharge,because of the spring not pushing the cyclinder back! fingers crossed it solves it

thanks for your imput tho,much appariciated!

Sounds like you're getting to the bottom of it. A weeping wheel cylinder will definitely cause issues, and the return spring was obviously your binding problem.
I found to get rid of the double push thing on the pedal I had to adjust the brake pads up to just rubbing.

oh yea im getting there,just i need it back on road by wednsday,so im abit pushed for time,and cant get any parts today, i can get a spring,but not the wheel cyclinder,bloody briptpart wheel cyclinders,they r ****e,they'v only been on there about 2 months! will have to go round all the others now! thanks for the imput anyways much appriciated!

rite! update,have fitted the return spring,and the new wheel cylinder,and hasnt made any difference atall,just no middle point to the adjustment,if the pedal is too high,u back the rod off the tiniest bit,and it just goes to the floor again wtf is wrong with it,im just clueless now,its had two new mastercyclinders,and 5 new wheel cylinders!! no leaks, nothing,just wont work in the way it should! maby i should try another master cylinder!

well i got a pedal,but you have to pump it twice to get it,but looking at the rear drums,and the shoes i think it wants new ones,so overhaul kit here we come,they are down to the rivets! the shoes are abit low on the rear,and the drums and shes on the front are grooved and pitted,so ill just overhaul the whole lot, and maby just put a new master cylinder on it! thanks for everyones input anyways!! ill get there eventuly!! never give up on the old girl,its lasted 34 years or so!

Let us know once you've done all the shoes and pads mate. Takes the **** sometimes, you spend so much and pit so much work in that you can only go forward. More money and more time. Should be grand when you're done though

Yeah thats the way I went. Full rebuild on front and rear brakes. At least that way you can be sure they are there when you need them.
The other thing to check is that you get the correct size slave cylinders. I had the same size front and rear on mine which gave me the double pedal push. Yours is probably caused by those pads though.
I ended up putting a lwb master cylinder on mine and upgrading to twin leading shoe on the front.

yea the rear shoes are pretty worn,rite down to the rivvets,and the front drums and shoes are all groved! but yes ur quite rite,iv always said,one thing you shud never scrimp and scrape on,on a car,are ur stopping tools! brakes!!! its had new cylinders,mastercyclinder,so shoes,drums,and springs here we come! but yes i think thats the reason,on the first pump of the pedal,you cant hear the shoes making contact,but on the second when you have a pedal,you can hear the shoes contacting the drums!! if this dosent work,i know you can get bigger bore mastercylinders,so ill do that next!! thanks for the replys!!

well i dont the shoes and drums on tuesday,yestarday,and the pedal is spongey as hell,and there are vertualy no brakes atall,and iv beld the hell out of em! ahhhhhhh what is up with them man! and the front drivers side drum dosent sit on the hub properly,and when you bolt the wheel on it binds on! :Cry: ill drive it for a wek and see if they get any better or not!

Spongy could either be because the shoes need to bed in, air, or possibly bulging front or rear flexi hose. Get someone to push hard on the pedal while you feel all the flexi hoses to see if one is bulging. I think it might just be that they need bedding in though. Mine took ages to bed in until I drove through loads of sand. After that they bedded in real quick. Adjust them up again and see how it feels then. Unless its REALLY spongy then it must have air. How are you bleeding them?

I've had this problem last year on mine. Here's some suggestions that not been said to do and check:
Twin leading cylinders need a bigger master cylinder they have more fluid to push. The front brake pipe from master cylinder need to be in the correct port, if you look at side on view of matter cylinder it might look fatter at the rear so the front brakes go from here. I'll try and find a url with the info I used.

The adjuster snails might not actually be touching the brake shoes, replaced my tls 11" shoes last week and found this out, had to look behind shoes with a torch and the shoe just needed a pull out and press back onto back plate.

Silly question: your shoe return springs do sit behind your shoes?

To test and eradicate any problems with the master cylinder, clamp off the three rubber hoses, one under rear end and the two at each front hub. Use proper clamps, g/c clamps or with care mole grips or with greater care glamorous assistants with pliers.
Check fluid level good.
Try brake pedal.
It should move about #### all!

You can also clamp just two of the rubber pipes to test each front separately or the rear circuit.

And you need to bleed the four corners in a particular order too.

With the drum not sitting square it's most probably a simple thing. The retaining screws are often needed to be drilled out as they may have seized. Not always replaced but the wheel holds it all together. When you put it back on the remains of the screw are not in a hole on drum but against a solid bit. Can't remember how many on rear but the front has three so easy to miss one if you got any others.

Hope this helps you, let us know how you get on

http://www.expeditionlandrover.info/dual_brake_conv.htm

Scroll down to step 4 about the master cylinder info. It is an American site but info still applies.